Approaches have been developed for cleansing the blood of toxins and waste products based on peritoneal dialysis, in which dialysate is introduced into the patient's peritoneal cavity. For example, U.S. Pat. No. 7,169,303 to Sullivan describes passing dialysate into a patient's peritoneal cavity, then withdrawing the dialysate from the peritoneal cavity and passing the withdrawn dialysate through an extracorporeal treatment system that includes a sorbent suspension for toxin removal.
U.S. Pat. No. 8,012,118 to Curtin describes a wearable dialysis system for removing uremic waste metabolites and fluid from a patient suffering from renal disease, in which a small external pump continuously recirculates peritoneal dialysis solution between the peritoneal cavity, where uremic waste metabolites diffuse through the peritoneal membrane into the dialysis solution, and a replaceable cartridge that cleans the solution and that may be replaced when the various layers become saturated. Curtin describes that albumin can be added to the peritoneal dialysis solution in the removal of protein-bound toxins and that a bacterial filter may be used to remove bacterial contamination from the solution. Curtin further describes that the fluid loop includes a replaceable drain container that drains excess fluid that has been added to the peritoneal dialysis solution through osmosis from the patient's body. A plurality of hollow fiber membranes may be connected to the patient's blood stream via vascular grafts to remove excess fluid from the blood stream, and that such excess fluid may be drained to the patient's bladder.
In view of the above-noted drawbacks of previously-known systems, it would be desirable to provide methods and apparatus for using an implantable device having a minimum number of parts requiring replacement, avoids the need for the patient to handle multiple types of fluid, and reduces the risk of infection, and allows for continual physician involvement.